Frame dumping trailers

Raspy · Mar 13, 2011

It looks like the pivot points are approximately even with the front spring pins. Are you careful to load the trailer for dumping balance?

wdchyd · Mar 13, 2011

After taking off the retainer nuts (to tilt)....I tilt to ground and gravity takes over (balance is important)......the pivot pins raise up when tail is on the ground..... it's all in the geometry and this would not work with small wheels/short axle or long bed.......

The other consideration is the pivot pins could be moved forward (didn't have to) if dumping is too tough to accomplish......this would increase the angle when the tail is on the ground....

QRTRHRS · Mar 13, 2011

56FordGuy said:
I was thinking about this the other day. It seems like a majority of the semi truck 'wagon' trailers are of the frame- dumping variety. Set the trailer brakes, unlatch the tongue, and put the truck in reverse. The hitch of the truck pushes the tongue of the trailer, which is attached to a pivot and causes the trailer to dump.

My question is, why don't we see more pickup truck sized trailers designed this way? It seems like it would be a lot simpler to manufacture than a hydraulic dump trailer. The only issues I can think of are one, the tow vehicle would need to have a trailer brake controller in order to lock up the brakes in order to make it dump. The only other that comes to mind would be tongue weight. Unless the trailer axles were mounted on their own subframe, they would need to be mounted further toward the rear of the trailer to allow it to dump to 45* without the bed of the trailer contacting the ground. When traveling, that would create more tongue weight on the tow vehicle. I suppose it would still work if the trailer bed contacted the ground and picked the axles up while dumping, though it could be tricky if on pavement and the edge of the bed wasn't able to bite into the ground.

What do y'all think?

Truss trailers sort of work like this. The kingpin is on a big baseplate with hydraulics that raise the front of the trailer up maybe four or five feet or so. The trailer wheels and suspension are pinned to the trailer frame somewhat like a standard trailer. Pull the pin then back the trailer up with the stationary suspension staying put allows the trailer to drop to the ground. They have big rollers on the rear of the trailer and rollers spaced out every so often on the trailer deck. Release the deck rollers, the load rolls off somewhat then you pull forward to pull the trailer out from under the load.

This all sounds good in theory but in practice can get pretty interesting. Sometimes the load won't slide so you have to gun it a bit going back. Occasionally, the back of the truck tractor ends up off the ground.

Duffster · Mar 13, 2011

QRTRHRS said:
Truss trailers sort of work like this. The kingpin is on a big baseplate with hydraulics that raise the front of the trailer up maybe four or five feet or so. The trailer wheels and suspension are pinned to the trailer frame somewhat like a standard trailer. Pull the pin then back the trailer up with the stationary suspension staying put allows the trailer to drop to the ground. They have big rollers on the rear of the trailer and rollers spaced out every so often on the trailer deck. Release the deck rollers, the load rolls off somewhat then you pull forward to pull the trailer out from under the load.

This all sounds good in theory but in practice can get pretty interesting. Sometimes the load won't slide so you have to gun it a bit going back. Occasionally, the back of the truck tractor ends up off the ground.

You have been there and done that. LOL

Sometimes roller trailers work best in "theory".